(a) Field of the Invention
The invention relates to a screening method of to identify individuals at risk of developing diseases associated with different polymorphic forms of wildtype p53.
(b) Description of Prior Art
The cellular tumor suppressor protein, p53, is one of the major regulators of cell proliferation. Depending upon the context of the stimulus, p53 will induce cell growth arrest or programmed cell death (apoptosis). As a consequence this prevents continued proliferation of cells which have acquired DNA mutations and this regulation represents one of the organism""s key defenses against cancer. In many human tumors inactivation of p53 is one of the principal factors in the development of the tumor. In Human Papillomavirus (HPV) associated cancers, however, p53 is almost always wild type. This is due to the activity of the viral E6 protein which labels p53 for ubiquitin mediated degradation and thus overcomes normal p53 functions. For this reason, HPVs are a major carcinogen for the development of cervical cancer in women, one of the most common forms of cancer world wide.
Two polymorphic forms of p53 exist which can encode either proline or arginine residues at amino acid position 72 of the p53 protein. This polymorphism results in a change in the migration of the p53 protein in polyacrylamide gels but, to date, both forms of p53 appear to have indistinguishable levels of activity. Indeed, numerous epidemiological surveys have been performed over the last 6-7 years in order to determine whether either polymorphism represents a risk factor for the development of several human tumors. Until now, the evidence has been overwhelmingly in favor of the view that the presence of proline or arginine at amino acid position 72 is not a significant risk factor in the development of any particular cancer.
However, based on our recent observations, it would be highly desirable to be provided with a screening method of to identify individuals at risk of developing diseases associated with different polymorphic forms of wildtype p53.
One aim of the present invention is to provide a screening method to identify individuals at risk of developing diseases associated with different polymorphic forms of wildtype p53.
In accordance with the present invention there is provided a screening method to identify individuals at risk of developing wildtype p53 related diseases; which comprises the steps of:
a) obtaining a biological sample from said patients; and
b) determining the presence of p53pro or p53arg wildtype alleles in said sample; wherein the allele pattern of patients selected from the group consisting of p53pro/p53pro, p53arg/p53arg, p53pro/p53arg are indicative of a risk factor for developing disease.
The diseases may be selected from the group consisting of neoplasia, cancers, viral infections and viral pathologies which may (or may not) be caused by a virus.
Such viruses include, without limitation, human papillomaviruses, hepatitis B, adenoviruses or any other viruses which infect humans.
More particularly, the diseases include, without limitation, cervical warts, cervical neoplasia or cervical cancer.
For example, when a patient allele pattern is p53arg/p53arg it is indicative of an individual at greater risk of developing diseases including cervical warts, cervical neoplasia or cervical cancer which are associated with human papillomavirus (HPV) infections.
Viral pathologies also include skin cancer caused by human papillomaviruses, and including long term viral infections and susceptibility to initial viral infections in individuals who are p53arg/p53arg. More precisely, the determining of step b) of the present method consists in at least one of but not limited to:
a) amplifying by polymerase chain reaction;
b) sequencing DNA or protein;
c) hybridizing with at least one probe specific to either p53pro or p53arg DNA; and
d) immunodetecting with at least one antibody specific to either p53pro or p53arg protein to identify the p53pro or p53arg alleles.
The screening method of the present invention may also be used to screen for patients which are under immunosuppressing therapy and are more susceptible for viral infections and viral pathologies.
In accordance with the present invention there is also provided a screening method for potential vaccination candidates in any HPV vaccination program, which comprises the steps of:
a) obtaining a biological sample from said patients;
b) determining the presence of p53pro or p53arg wildtype alleles in said; wherein p53arg/p53arg patients should be preferentially vaccinated.
In accordance with the methods of the present invention, the patients may have an abnormal PAP smear, low grade cervical lesions, may be newborns, or newborns to mothers with genital HPV infections.
For the purpose of the present invention the following terms and abbreviations are defined below.
xe2x80x9cDiseases associated with different polymorphic forms of wildtype p53xe2x80x9d is intended to mean any diseases involving p53 and wherein wildtype p53arg or p53pro behave differently. Such diseases include, without limitation, cancers caused by viruses such as papillomavirus.
xe2x80x9cp53argxe2x80x9d is intended to mean p53arginine, wherein an arginine is found at amino acid position 72 of the p53 wildtype protein.
xe2x80x9cp53proxe2x80x9d is intended to mean p53proline, wherein a proline is found at amino acid position 72 of the p53 wildtype protein.
xe2x80x9cHPVxe2x80x9d is intended to mean human papillomaviruses.